PowerPoint is good but keep it simple. Very little text on each slide. Plain fonts and no cheesy transitions (first time PowerPoint users always do this - it's crap). I've always hated how at the beginning of PowerPoint presentations you get to see all the slides at once, (see fig. 1), it's bad software but try to get round it. It can also be a bit bad with QuickTime movies so have them available on the desktop as well, just in case.

Director is disappearing but was always good because you had more control over the slides, animations and video. The one problem I always had was remembering where I put the buttons (I often made them invisible) so keep a convention for yourself or make them really obvious. Because when you show something (maybe a few months after you made it) you might not remember how to click through your own work (embarrassing in front of 5 managers from Sony).

Processing is not as such a presentation tool and I'll discuss it properly at another point but can be used to make great on-screen examples among other things. Just make sure you remembered what you called all your projects, so you open the ones you want in the order you want.

Video, on DVD, VHS or QuickTime, is great. You can pre-prepare it, and time it, and it usually plays with no problems. But there are some things you need to remember. Don't put music on unless it really needs it and if you do, then make it subtle; nothing too obvious or jarring. If you need to tell a story then keep it simple. Show it to your friends, see if they understand it. Also keep videos down to the essentials. Grand sweeping vistas are good for Hollywood but might not be relevant to your video of a new phone address book interface.

Working prototypes are really great. If you have an on-screen or physical prototype (even if it's faked or mocked up), show it. Don't show a grainy QuickTime of an amazing interactive object, when the real thing is on your desk and working. People love stuff that works or even more importantly, seems to work. You will capture their imaginations and give them a sense of reality. But be warned, prototypes that don't work can have the opposite effect, so make them robust.

Put on a show. If you need a scenario and can't make a video or don't want to, then do it live. Rope in some friends to act out the scenario. Fake up little things like someone phoning you during the presentation, which gives you a chance to show the product (phone service etc). Alter the lighting, wear a costume, sing a song. It's all valid as long as it serves the idea.

Finally, when working with on-screen presentations get your work onto the machine you are going to use in good time and test it!